This invention relates generally to wireless devices, and particularly to wireless devices with a reduced power consumption mode.
A wireless device such as a cellular telephone may include two processors. One processor may be responsible for baseband processing and the other may be responsible for handling non-wireless applications such as telephone logs, call functions and the like. In other wireless devices, one processor may execute both communications functions and applications. Regardless of the number of processors, separate communications and application subsystems may exist.
In portable embodiments, preservation of battery life may be very critical. Thus, portable wireless systems may adopt reduced power consumption modes to increase the time between battery charges.
One of the two subsystems may power down to save power while the other one is still powered up. This may result in ineffective power consumption conservation.
Also, one of the subsystems may constantly call on the other subsystem, while the other subsystem is in the power conservation mode, in order to implement certain functions. Thus, each subsystem may constantly be pulled out of its lower power consumption mode by the other subsystem.
Generally, processor-based systems progressively power down. Some processor-based systems have several power consumption states. Based on a triggering of event such as lack activity, the system may power down to a lower power consumption state. After a period of continued inactivity, a system may power down to an even lower power consumption state.
If activity occurs, the system may then transition progressively to successively higher power consumption states. Because there is a time delay between the triggering event and the resumption of a full active state, it is undesirable to prematurely power down the system. In addition, performance of the system may suffer if the system is continually powering down and then immediately powering back up.
Because the communications and application subsystems are separate, their power consumption modes may tend to conflict. When one subsystem wants to power down, the other subsystem may need to be powered up. This may result in inconsistencies between the two subsystems. In addition, one subsystem may constantly cause the other subsystem to return to its full power consumption state.
In effect, each subsystem may constantly pull the other subsystem to a higher power consumption mode. This may result in system inefficiencies as well as increased power consumption.
Thus, there is a need to improve the power consumption operation of communication and application subsystems.